Nov 3, 2023 Nepal earthquake: Source mechanisms and structural response of Indo-Gangetic basin

The 2023 Nepal earthquake is one of the major earthquakes in the Himalayas after the 2015 Gorkha earthquake. The shaking from the earthquake was felt strongly in Nepal and parts of Indo-Gangetic basin. In this study, we estimate the source mechanism of the earthquake using regional and teleseismic broadband seismograms, and polarity information from local RaspberryShake seismome-ters. We further simulate the moment tensor solution for the 2023 event in a three-dimensional medium using the spectral element method. This region is of particular importance because of extreme topographic variations, large crustal thickening beneath Tibet, and the presence of thick Indo-Gangetic sedimentary basin. The structural model used for simulation includes the basin and the topo-graphical variations. With this simulation, we compare peak ground velocity (PGV) values at basin and non-basin sites. The results are useful for hazard assessment and mitigation by characterizing places with higher potential for ground shaking.